Career
He was a leading expert on Mesozoic fish and reptiles. He worked as a curator at the Muséum d"Histoire Naturelle in Boulogne-sur-Mer, and published extensively on Late Jurassic dinosaurs and other vertebrates from the Boulonnais region of northern France. He made important contributions involving vertebrate palaeontology in Portugal, describing in 1897, Suchosaurus girardi from jaw fragments found in that country.
From 1883 to 1896 he served as director of the station aquicole in Boulogne-sur-Mer.
The plesiosaurid species, Lusonectes sauvagei commemorates his name, as does the crustacean species Pseudanthessius sauvagei.